By ROSALEEN MACBRAYNE
OPOTIKI - Freeze-dried rats are being used to trap stoats in the northern Urewera National Park, where Department of Conservation staff are battling to save endangered birds.
The bait has proved a hit with the wily mustelids, which are a bane to kiwi chicks. In turn, the rats are easily drawn into traps by the lure of peanut butter.
"Rats love it. Don't ask me why, but they just can't resist it. Peanut butter is like Camembert cheese and champagne to them," said Pete Shaw, the Opotiki conservation officer managing the ecosystem restoration project.
Stoats, however, are much harder to outfox. "They are really intelligent, cunning and variable in their behaviour. But we think all stoats will eat rats because that is their main diet component or prey species."
The innovative method of using one predator to catch another was dreamed up after Tuhoe, the Urewera tangata whenua, objected to poisons.
"We thought: 'All we need is a long-lasting rat'," said Mr Shaw, who came up with the idea of freeze drying, which leaves the rodents "still looking and smelling like a rat."
After an encouraging trial scheme, the Department of Conservation is "cautiously optimistic" that freeze drying bait species may be adopted in other parts of the country.
Late last year, 300 rats were trapped in the northern Ureweras near Waimana, freeze dried by an Auckland firm and sent back to the eastern Bay of Plenty.
From February until the end of June, they were hung in tunnel-like containers between two spring-loaded traps. During the trial, 48 stoats were caught in rat-baited tunnels and only seven in the standard egg-baited tunnels.
Mr Shaw said some fine-tuning was needed before the programme resumed in September, the next bird breeding season.
Dried peanut-butter rats trap wily stoats
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